Apparatus for drying, burning, and recovering finely-divided materials



April 28, 1925.

APPARATUS FOR DRYING, "BURNING J, N. A. $A UER AND RECOVERING FINELY'DIVIDED MATERIALS: Filed May-2s, 192s B "ff- N ii I 1 1 ii 3 f 11 \J I" h lii N i w I A Q) m U .3 v) A 3% N INVENTOR.

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J. N. A. SAUER- j APPARATUS FOR DRY ING, BURNING AND RECOVERI'NG FINBLY DIVIDED MATERIALS Filed may 26, 1923 4 Shets-Sheet 2 BY a A TTORNEYS.

April 28, 1925. 1,535,949 J. N. A. SAUER AFIFJKFJUIUS FOR DRYING, BURNING; AND RECOVERING FINELY DIVIDED MATERIALS Filed May 26, 1925 1 4 sheets-sheet 5 Waste Gases v 44 Steam 0r Wafer det Condenser fiafile A I I i Retort i s IINVENTOR. cZUWuQdauefl max:

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April 28,1925. 1,535,949 Y J. N. A. SAUER APPARATUS FOR DRYINGQBURNING, AND RECOVERING FINELY'DIVIDED MATERIALS Filed May 26, 1923 4 Sheets-Sheet 4 INVENTOR. 6 came/1%.

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Patented Apr 28, 1925.

UNITED STAES OFHCE.

.errnnarns ron DRYING,

BURNING, AND RECQVERING FINELY-DIVIDED MATERIALS.

Application filed May 26, 1923. Serial No. 641,775.

To all whom z't may concern:

Be it known that I, J QHAN NICOLAAS ADoLr SAUER, residing at Amsterdam, Netherlands, have invented certain new and 5 useful Improvements in and Relating to an Apparatus for Drying, Burning, and Recovering Finely-Divided Materials, of which the following is a specification.

The invention is an improvement in the apparatus for the revivifying or burning of finely powdered adsorbent materials, e. g.

decolorizing carbon, kieselguhr, fullers earth and the like.

Experiments have shown that for the uninterrupted and efficient operation of the apparatus, it is of greatest imortance, in the reviviiication by heat of ely powdered materials such as decolorizing' carbon, to arrange for quick and regular, and preferably uninterrupted removal of the evolved gases and vapors which are formed by the drying and burning of the mass.

In order to obtain a quick removal of the evolved gases and rapid condensation with prevention of obstruction, it has been found to be necessary that the condensation and dust collecting device should consist of a plurality of units, each unit being arranged adjacent or connected to, one end f the heating or proximity by short thereto, and connected therewith and preferably wideconduits,

as flue gases, but arranged for example outside the brickwork of the furnace and which short conduits can be cleaned from the outside.

A further characteristic, to allow of uninterrupted operation of the furnace, is the provision of more near and'connected to the receiving tank for the heated or burned material leaving the last retort. The first tank may thus be water sealed and the entrance of air into the first (receiving) tank thus prevented.

Moreover the quantity of evolved gases 'in the retort must be as small as possible, as it is these evolved gases which carry along the fine particles of the product, and

tend to obstruct the outlets so as to prevent the production of a highly active mass, as lIl'ZSllGll case the decomposed tarry distillation products are not su'flicient-ly removed.

burning cylinders and inpreferably not exposed to direct heat such than one tank placed This requires gradual drying of the material before same is exposed to high temperatures.

The improved apparatus is designed with the following objects in View:

To reduce to a minmum the quantity of evolved gases or'vapors in the cylinders or retorts.

To construct the apparatus in such way, that the conduits leading from the cylinders to the condensation device are as wide and short as possible.

To provide for these connecting conduits being easily cleaned from the outside.

To allow of easy removal of the recovered material and of the condensation products from the condensation device.

To allow of an uninterrupted operation ofthe apparatus.

With the object of obtaining the above mentioned advantages, a pre-drying' conveyer with a mechanical propelling device is used, in which the wet material to be burned is first pro-dried, but preferably without proceeding to such a degree of dryness as to cause the product to enter the retorts in a perfectly dry state, as otherwise there would be excessive production of dust and consequent loss.

Pro-drying tanks or other suitable devices may be us d for the pre-drying, and these may be i1 combination with the above mentioned PI'GTE ying conveyer.

Furthermore there is preferably a plurality of, or at least two condensation devices, which may for example be placed at both ends of the retorts or cylinders so that the connection to the retorts is as short as possible.

The vents for the gases from the retorts are arranged at a part outside the zone where the heat or the hot gases surround the retorts, e. g. outside the brickwork of the furnace, where in the case of a plurality of' cylinders the unions between the same are arranged.

Furthermore the device allows of removing a large quantity of the condensible gases beforehand at a low temperature, so that the evolving of gases in the retorts proper is limited to those products of decomposition which are formed at a higher temperature.

The invention will now be described more fully with reference to the accompanying drawings, which illustrate one form of a construction embodying the improvements.

Fig. 1 is a front elevation of the apparatus, with parts broken away.

Fig. 2 a top plan view.

Fig. 3 a side elevation seen from the right of Fig. 1.

Fig. 1 a side elevation seen from the left of Fig. 1.

Gases and vapors evolved by the drying and burning of the wet material may escape from: (1) the pre-drying conveyer 1, (2) the upper retort 2, the lower retort 3, through wide tubes 5, 6, 7, and 8 connected to the retorts and to the vertical condensers 9 and 10. 1, 2 and 3 are provided with suitable means for feeding the material through them. The drawing showing this in the form of conventional feeding screws, illustrated in Fig. 1.

A plurality of retorts and a plurality of pre-drying conveyers as well as a plurality of condensation devices may of course be used, in case the apparatus is to be of a large capacity. The condensers may be filled with a quantity of Water up to the overflows 17 and 18. In the condensers a draft is produced by means of the chimneys 11 and 12.

Each condenser is divided vertically, to within a short distance above the liquid level by means of a vertical partition 2. Escaping gases and light particles enter the condensers through the tubes 5, 6, 7, 8. The water vapor is condensed in the condenser by cooling by means of air or water, and the solid particles of dust are carried down by the condensation products (water) and collected in the water at the bottom of the condenser. I

The uncondensible gases are carried away through the chimneys 11 and 12. 1

According as the moisture content of the material to be revivified is higher or lower, the deposits in the condensers will be of a more or less solid nature.

If the moisture content is too low, then cakes will be formed in the upper parts of the condensers in consequence of the adhering properties of the finely powdered material, especially carbon. The escape of the gases may thus be prevented. For this reason finely divided water or steam is injected into the upper part of the condenserthrough sprayers (atomizers) 14, in case rather dry carbon is to be treated, and this will prevent the particles of carbon from caking together. The spraying may be regulated by means of valves 15, 16. The surplus of condensible products and water is drained off automati cally by the overflows 17, 18, and these also lieepl the water in the condensers at the same eve.

The condensers are emptied once or twice daily, in order to recover the carbon contained therein. This carbon will have formed a deposit on the bottom of the condensers. By means of'compressed air from the pipe line 19, 20 the water' in the condensers is mixed with the carbon and this mixture, rendered sufficiently liquid, may be carried away by means of an injector21 or a pump. 1

Asithe overflows 17, 18 are fitted with a siphon, no air can enter the condensers, as the lower part of the siphon is always filled with water.

22,23, are water supply cocks.

24, 25 are test cocks. I

In order to allow of uninterrupted opera- 'tion of the furnace a second -tank 27 is placed beside the receiving tank 26. Tank 26 may be closed hermetically by a cover 28 and a stufling box 29 placed around the mixing shaft 30. Mixing arms 31Akeep the contents in motion to prevent the settling of solid particles.

From the lower part of the tank 26 a con necting pipe 32 with a valve 33 connects with the outlet of tank 27. Tank 27 also has a mixing shaft 34 and mixing arms 35, but is open at the top. The level and the density of the liquid in both tanks may be ascertained by'looking in tank 27. The valve 33 is only used in case one of the tanks is to be cleaned or re aired.

- The suction pipe 36 and valve 37 of the pump are connectedto tank 27, the connecting being made in such a Way that a certain quantity of Water will remain in said tank after pumping the deposit away. This prevents the entrance of air into tank26. The

emptying of the both tanks can be effected I water is sucked away through pipe 40, which also is connected with the condenser 9.

The greater part, of the water vapor formed in the pro-drying device according to this improved system directly removed and does not enter the retorts,

consequently cannot cause the carrying off of large material.

The whole device is compact and practical and does away with the necessity for continuous cleaning of the connecting conduits which carry away the gases.

The pre-drying conveyer trough is closed quantities of fine particles of the and has two closable openings, one-at the part where the material is fed into the trough and one at the is connected with the upper retort.

By using an ascending connection between conveyer, is by the part where the trough the pre-drying trough and the condenser a regular removal of the vapors is obtained.

The ends of the retorts 2 and 3 extend outside the brickwork into proximity with the two condensation devices 9 and 10.

The condenser 10 is provided with connections 5 and 6 from the retorts, having short T tubes 42, each closed by a removable plate 43.

The other condenser is also provided with connections 7, 8, from the retorts 2 and 3 respectively.

Vhat I claim is:

Apparatus for the cgntinuous drying and heating of finely divi ed material and especially suitable for revivifying spent decolorizing carbon, kieselguhr, fullersearth rality of drying and burning chemical means fbr'moving solid n aterial through aid retorts, and condensation and dust coll cting apparatus, which condensaand the like adsorbents, comprisinga plureto ts, inc-- 'tion and dust collecting apparatus is com posed of a plurality of units, each of which for the solid material recovered in said condensing apparatus, said tanks communicating with each other, one of said tanks being closed by a Water seal and serving for,directly receiving said solid material, said other tank being provided With means for removing the treated material.

In testimony whereof I my signature in presence of two Witnesses.

JOHAN NICOLAAS ADQLF SAUER.

lVitnesses E. HOLFERMAN, C. E. VOGEL. 

